1. Field of the Invention
The invention relates to a vehicular lamp, and particularly relates to a vehicular lamp having a planar light source in which an organic EL light emitting layer is formed on a substrate.
2. Description of Related Art
With the recent prevalence of an organic EL panel, the use of the organic EL panel as a light source of a vehicular lamp is proposed (see Japanese Patent Application Publication No. 2013-45523 (JP 2013-45523 A)). In general, the organic EL panel is configured by forming an organic EL light emitting layer on one side surface of a transparent substrate and sealing the organic EL light emitting layer with a sealing plate. A positive electrode layer is formed on the front side (substrate side) of the organic EL light emitting layer, and a negative electrode layer is formed on the back side (sealing plate side) thereof. Hereinafter, the positive electrode layer and the negative electrode layer are collectively referred to as “electrode layers” appropriately. An area of an end portion of each of the electrode layers extends to the outside of the organic EL light emitting layer in the substrate for connection with an external power supply terminal. In addition, a joint portion between the sealing plate and the substrate is formed so as to surround the organic EL light emitting layer. Accordingly, in a peripheral edge portion of the organic EL panel, a non-light emitting portion that surrounds the organic EL light emitting layer is formed.
The organic EL panel described above emits light flatly, and hence the organic EL panel can be used as, e.g., part of a rear combination lamp or a side marker lamp. In this case, the organic EL panel is installed at a predetermined position in a lamp chamber, and the substrate is fixed to a lamp body such that a light emitting surface of a planar light source opposes an outer cover.
As described above, the organic EL panel has the non-light emitting portion in the peripheral edge portion, and the non-light emitting portion cannot be used as the light source. Accordingly, for example, in the case where a light-emitting portion is arranged with taking a design quality as a vehicular lamp into account, the installation mode of the organic EL panel in the lamp chamber is limited.